1. Field of the Invention
The present invention relates to an improvement in a joint designed to couple pipes made of metal or tube made of resin (hereinafter simply referred to as a pipe) which is relatively small in diameter, typically, less than 20 m/m and is adapted to supply oil or gas, for example, to an automotive vehicle or other various machines and instruments.
2. Description of the Related Art
A conventional joint of this type is shown in FIG. 7 and has a body 11. The body 11 includes a cylindrical joint wall 12 defining a bore 14, and a continuous cylindrical wall defining an enlarged chamber 13 in communication with the bore 14. A support wall 11' extends rearwardly from one end of the cylindrical wall. A seal and a bushing are disposed within the enlarged chamber 13. A socket 18 includes a stepped annular wall 18' engaged with the support wall 11'. A plurality of pawls 15 extends forwardly and inwardly from the socket 18 and are inserted into an elongate bore 19 of the cylindrical wall of the body 11. A pipe Po has an annular projection wall Po' located within the enlarged chamber and engaged with the pawls 15.
In the prior art, the stepped annular wall 18' of the socket 18 is engaged with the holder wall 11' of the body 11. At the same time, the pawls 15 of the socket 18 are located within the elongate bore 19 of the cylindrical wall of the body 11. With this arrangement, however, the base 18" of the pawls are pressed when the socket 18 is fit through the holder wall 11'. This inevitably results in an increase in the diameter of the socket per se and thus, the joint as a whole as well as the length of the joint. Consequently, the joint can not be fit in a small space. In addition, the projection wall must have a large diameter. The long pawls can not otherwise be securely engaged with the projection wall. This causes "settling" and consequent leakage when the joint is subject to vibrations. The joint is thus not effectively operable if used for a prolonged period of time. A further problem with the prior art joint is that engagement of the pawls 15 within the enlarged chamber Po' can not be visually monitored.